I believe trying to develop a cross platform IDE is a virtue. The experience is more educational and makes developers aware of other peoples needs, not just Windows users. I use Code::Blocks on both Windows XP and Ubuntu Linux and am eternally greatfull that time was taken to support other operating systems. The fact that the developers are trying to achieve this with Code::Blocks deserves some respect.
The whole point is having a familiar tool available in difference OSes. It expands the community of the project and at the end of the day, the more people involved the higher the quality becomes .For C++ Code::Blocks fits this description and that is why use it.
Regarding RC3, I think the fact that nightlys are supplied is a saving grace. But i would still be nice to see a official release :-)